Installation apparatuses for an elevator include a safety gear, a governor, and the like. These apparatuses enable a car of the elevator to brake emergently when the car exceeds a particular speed, to avoid an extreme accident such as freefall of the car.
An existing governor mainly has the following two functions: In the first aspect, the governor triggers an electrical switch to disconnect a safety circuit when the car accelerates to a first limiting speed, so as to brake the car by using a holding brake of a traction machine. In the second aspect, if braking in the previous first aspect fails and the car continues to accelerate to a second limiting speed (the second limiting speed is greater than the first limiting speed), the governor draws a steel rope connected to a wedge of the safety gear, to actuate the safety gear, thereby braking the car thoroughly. The function in the second aspect needs to be implemented mechanically, so as to ensure extremely high reliability.
However, after completing the functions in the foregoing two aspects once, the governor needs to be reset to an original position so that it can still complete the functions in the foregoing two aspects during a subsequent operation process of the elevator. Especially, the governor needs to be mechanically reset to restore the function in the second aspect.
For an elevator in which the governor is installed at a position easily reachable to an operator, that is, for an elevator with a machine room, it is relatively easy to implement mechanical reset of the function in the second aspect. However, for an elevator in which the governor is installed at a position difficult to reach or unreachable for an operator, that is, for a machine room-less (MRL) elevator, implementation of the mechanical reset of the function in the second aspect needs to completely rely on the governor, that is, mechanical reset is implemented without a manual operation.